Frequency Offset, "offset (in ppb)

Ian1

In the Radio Setup using 15Mhz I am now getting a reading of -684 ppb is this level acceptable?

Ian

Bob Brown - N8OB

Mine runs at +480 and is correct.  The reading you are getting sounds like you are not seeing 15Mhz correctly.  Have you tried it on 10 Mhz?

Greg N8GD

I don't know if the radio compensates for it or not, but I always try to do the calibration during the portion of the WWV signal when there's no tone modulation.  Listen to the signal before you run the calibration routine and find out when the tone is not there - the last 15 seconds of most minutes, if I recall correctly.  I also seem to have had better luck with 10 MHz even if the propagation favored the higher frequencies on a particular day or at a better time of day.

Last time I calibrated mine (a few months ago, after they fixed the problem with the calibration not working in SSDR), my 6300 has an offset of -127 at 15 MHz (looks like I don't follow my own frequency advice!).

Greg - N8GD

Bob Brown - N8OB

If you use the calibration procedure on the radio, it takes the radio into 15Mhz or whatever freq you are using on WWV.  It will automatically adjust things correctly.

George KF2T

Yes, your value is well within acceptable limits. It will vary from measurement to measurement.

David Decoons, wo2x

my 6700 is consistently around -2300

Lawrence Kellar KB5ZZB

My 6700 is at -4000 ppb.  I have a help desk ticket opened for about a week waiting for an answer.  It is very stable though.  

George KF2T

This value is the correction applied to an internal component to bring the system to "exactly right." Whether or not it is a part per billion or 4 parts per million is not really important, as long as the value is relatively stable over time. A "large" value, as reported by Lawrence, for example, doesn't indicate a problem. It represents 8 Hertz correction (not error) at 30 MHz. If having a harmless value present makes you nervous, the GPSDO option may be for you.

Lawrence Kellar KB5ZZB

Thanks. All I needed to know was that it was ok. I just wanted to make sure it wasn't a symptom of a more serious problem I did learn however that you have to have your antenna connected to antenna one to calibrate. You cannot calibrate off of antenna two

Ian1

Gentleman

Thanks for all the info the past few months I have measured the WWV signal and have got a consistent -664 to -684 value.

Appreciate all the info as this feature other then how to use it doesn't mention a value that is acceptable.

Ian

Tim - W4TME

If the calculated value is out of range, an error occurs.  if you get a non- zero value, it is safe to assume that the test was successful.

Tim - W4TME

We calibrate on the carrier, not the tone pulses.

Tim - W4TME

The short answer is yes.  

Rick WN2C

Would you get different results using different offset frequencies for WWV?
I get slightly different results using different freqs from WWV. They all range from 128 to 118.
Just so I understand how this calibration works, it takes the offset and applies it to a device in the radio to correct it? And once applied it is exactly on frequency?

Tim - W4TME

Differences in atmospheric Doppler frequency shifting could account for it.

Once the calibration routine has run, the radio is on frequency within spec based on the frequency source using the offset calculated. 

Lawrence Kellar KB5ZZB

I just got word back from Flex. 4000 is out of spec and I will have to send my radio in. It looks like it is time for a nice leisurely drive to Austin. The last time I shipped the radio it cost me $120

Ian1

Thanks Tim

David Decoons, wo2x

Did they say what is considered maximum? Mine is around 2300 consistently. Dave wo2x

Lawrence Kellar KB5ZZB

No they did not.

Gerald-K5SDR

The answer is that if the frequency calibration function works and the frequency is stable your radio is operating properly.  It should always generate a non zero value it the routine has properly calibrated.  The stronger the calibration signal, the better the accuracy.  The higher the frequency of the calibration signal the higher the accuracy.  The absolute offset is not critical so long as calibration works properly.  Expect the values to change over time deviating further from zero due to normal aging.  

Gerald

David Decoons, wo2x

Thanks Gerald. Just making sure the 6700 is ok. I know after software upgrade you need to recalibrate. Dave wo2x

Ken - NM9P

Tim - W4TME

You do not need to re-run a frequency calibration of the 6000 after a software upgrade.  The frequency calibration is stored in the non-volital EEPROM.  A factory reset would not overwrite the XO offset data 

Ken - NM9P

Tim - W4TME

The only thing I am aware of in the code that would zero out the frequency cal offset data is if the radio thinks there is a GPSDO installed.

Ken - NM9P

Tim - W4TME

No.  It is stored in the EEPROM with all of the other radio calibration data.

David Decoons, wo2x

PA2TA

Just wondering, over here in Europe i get (very) different results for every attempt to calibrate my 6300. Which makes sense because WWV is far out of reach, i presume the radio does not switch to another standard signal for Europe?

SSDR v1.8.4.168
HW version v1.8.4.84

Tjakko PA2TA

Tim - W4TME

Tjakko,

I am aware of other time sources world-wide
http://www.dxinfocentre.com/time.htm

Just manually enter the frequency of one of them which is providing a strong signal into the calibration routine and use it.  Remember to press the Enter key after entering the new frequency.

PA2TA

Hi Tim,
Thanks for the response, at the moment the only usable station is RWM in Moscow on 4.996, it is abt S7 or -97dBm, the noise floor is at abt -100dBm. I still get very different results, varying from -12 up to +786, maybe the signal is not strong enough?

I will try some other freq's later, for now its time to call it a day.

Tjakko PA2TA